Distillation of coal and other carbonaceous substances



R. NISBET Dec. 3, 1940.

DISTILLATION OF COAL AND OTHER CARBONAC EOUS SUBSTANCES Filed March 11, 1938 6 Sheets-Sheet 1 R. NISBET 2,223,897

DISTILLATION 0F COAL AND OTHER CARBONA OEOUS SUBSTANCES Filed March 11, 1938 e Sheets-Shet 2 Inventor n V A AYA A'Y/x AVA VA /KV (AV V Dec. 3, 1940,

R. NISBET 2,223,897

DISTILLATION OF COAL AND OTHER CARBONACEOUS SUBSTANCES Filed March 11, 1938 6 Sheets-Sheet 3 Inventor w. 9. W 1 .dttorney.

R. N'ISBET DISTILLATION OF COAL AND OTHER CARBONACEOUS SUBSTANCES Filed March 11; 1938 6 Sheets-Sheet 4 Inventor f2. fmet:

Fig.6.

R. NISBET Dec. 3, 1940.

DISTILLATION OF COAL AND OTHER CARBONACEOUS SUBSTANCES Filed March 11, 1938 6 Sheets-Sheet 5 Inventor 1940- R. NISBET 2.223,'897

DISIILLATION 0F COAL AND OTHER CARBONACEOUS SUBSTANCES Filed March 11. 1938 6 Sheets-Sheet 6 Fig. 10. k

Patented Dec. 3, 1940 UNITED STATES DISTILLATION OF C BONACEOUS SUBSTANCES OAL AND OTHER CAR- Robert Nisbet, Barnet, England, assignor to British Smokeless & Oil Fuels Limited, London, England, a British company Application March 11 1938, Serial No. 195,278

In Great Britain December 7, 1935 4 Claims.

This invention relates to the distillation of coal and other solid carbonaceous substances and more particularly to apparatus for efiecting such distillation at low temperature.

According to the invention the carbonaceous substance is charged into containers that are caused to pass through an upstanding retort or carbonizing zone under the action of gravity and While subject to the control of a lowering de vice at the lower end of the retort or carbonizing zone, which lowering device is adapted to take the weight of the column of charged containers in the retort or carbonizing zone and may further be adapted to release the containers singly or in small numbers for the discharge of the coked residue or product of distillation.

Thus, the containers within the retort or carbonizing zone may be adapted to be supported in position one resting upon the other by mechanism comprising a plurality of supports for the said containers which are caused to pass into and out of the position for supporting the containers that are at any moment at the lower end of the retort or carbonizing zone, and to lower the said containers one or more at a time. The

supports may conveniently take the form of arms which extend normally to the length of an endless chain or chains adapted to pass about suitable sprocket wheels or the like. By suitabledisposition of the path of the chains or the like carrying the supports or arms in relation to the lower end of the retort or carbonizing Zone, it is possible to secure that the column of containers Within the retort shall be supported by the supporting arms, and that in the passage of the chains or the like about the lowermost sprocket wheel or the like the weight of the column of containers is relieved from the lowermost container which is then free to be disengaged from the corresponding supports or arms and to be delivered to the discharge valve.

Alternatively the supports or arms may be carried by a wheel of large size similar to a sprocket so set in relation to the lower end of the retort or carbonizing zone that the supports or arms are caused to have a relative movement in relation to the containers in the lower part of the retort or carbonizing zone, in such manner that the supports or arms as they are carried to the lower side of the wheel are caused to relieve the lowermost container of the weight of the column of containers within the retort or carbonizing zone. Other means having the same purpose may be used without departing from the invention.

charged containers released by the lowering device maybe caused to travel tothe position of discharge, wherethey are inverted for the discharge of thecokedresidue or product and are engaged by an elevating mechanism, such as a chain conveyor, for transmission to the upper end of the retort, by a path exterior to the retort, and to a charging mechanism by which the containers are recharged with the carbonaceous material for re-admission to the retort.

The chain conveyor or the like may be caused to have a speed oftravel for the containers that is in excess of that of the lowering mechanism, so that the return of the discharged containers to the upper end of the retort or carbonizing zone may be effected rapidly and a lesser number of containers than would otherwise be the case be required.

According to the invention, moreover, the containers may be introduced into the retort or carbonizing zone and may .be withdrawn therefrom by way of, sealing or closure valves permitting the introduction of. the containers into and their withdrawal from the retort or carbonizing zone one or more at a time. The sealing or closure valves may conveniently be provided in the form of radial valves disposed each within a corresponding containing casing suitably positioned in relation to the inlet or exit of the retortor carbonizing zone, and provided for the reception of one or more containers for the carbonaceous material at one and the same time. For this purpose the valves may be provided as drums each with one or more spaces therein of a form substantially .following that of the container or containers to be introduced into the valve, and such space or spaces may be positioned diametrically or parallel witha diameter according as the inlet of and the exit from the valve casing for the containers are disposed on. the diameter of the casing or on the diameter of the casing.

According to the invention, also, the charging of the containers may be effected from a supply bunker by such means as an interposed calibrator and the movements of the sealing or closure valves of the retort and of the valves or obturators of the supply bunker and of the calibrator, where such elements are present, or equivalent movements, are then effected by mechanism serving to ensure the required co-operation of the several parts in the charging of the containers and in their passage through the retort. Thus, means may be provided for effecting the oscillation of such parts as the inlet According to the invention, moreover, the

Ian

valve, the valve of the supply bunker and of the calibrator comprising one or more pawls or arms fixedly mounted upon a spindle capable of rotation and that are operated for oscillatory movement of the spindle by means of two cams that are caused to rotate either continuously or intermittently in opposite directions and are so disposed in relation to the pawl or pawls as alternately to move the spindle in opposite directions with the required timing, the spindle serving either directly or through gearing to operate the corresponding valve.

Such a driving mechanism may be provided in respect of each of the oscillatory elements or valves of the plant. Alternatively, since the movements of the oscillatory members or valves are co-related, a single cam and pawl mechanism may serve to drive all of them, the operating spindles of certain of the oscillatory members being connected to the first spindle by toothed gear, or, where advantageous, by link mechanism. 7

According to the invention, moreover, the containers may be caused to be retarded by suitable retarding elements when arriving at the charging position so that they arrive on the surface upon which they are to rest during the charging operation without shock.

According to the invention, moreover, in order that the container arriving at the filling position may be moved so that its mouth is brought into coincidence with the discharge opening of a fixed delivery chute that portion of the guide against which the container rests while in the position for charging is mounted pivotally and subjected to the action of operat ing mechanism by which it is caused to have an intermittent forward movement to throw the container resting against it into the position below the delivery chute.

According to the invention, also, means may be provided whereby the carbonaceous material in the supply bunker may be preheated by passage through the bunker of waste gases or heated air.

According to the invention, also, there may be provided a setting which extends along the length of the retort and is formed with a plurality of spaced combustion spaces disposed along the length of the retort and serving for the inlet of or generation of heating gases at a plurality of spaced positions whence the heating gases pass in one direction of the retort along the setting and are then brought into close proximity with the retort or retort chamber for flowing in a differing direction. Thus, the heating gases from the several spaced points of admission or generation may pass downwardly along the setting and may then be brought into contact with the walls of the retort chamber or the retort along which they flow upwardly to be exhausted from the setting at the upper end or at some other position as may be convenient or desirable.

The air for combustion may be introduced into the setting by way of fines or passages that extend parallel with and in close proximity to the fines or passages in which are formed the combustion chambers or spaces. The air fiues may thus extend throughout the length of the setting and at those positions at which combustion is required to take place the air flues may be provided to admit air to the said combustion spaces or chambers.

The invention is illustrated, by way of example, in the accompanying diagrammatic drawlngs.

Figure l is a side elevation, partly in section of a complete plant.

Figure 2 is a sectional elevation of the mechanism below the retort, to a scale larger than that of Figure 1.

Figure 3 is a sectional plan view of the casing ,of the container-supporting or lowering mechanism and of the lower extension of the retort.

Figure 4 is a sectional elevation of a valve casing and valve, with a container therein.

Figure 5 is a cross-sectional elevation of the valve and valve casing, with a container therein.

Figure 6 is an elevation of a construction of charging mechanism at the upper end of the retort and of the inlet valve.

Figure '7 is an elevation of the parts shown in Figure 6, taken from a view point 90 removed.

Figure 8 is a sectional elevation of a construction of setting for the retort.

Figure 9 is a sectional elevation of the setting shown in Figure 8 taken at right angles to Figure 8.

Figure 10 is a sectional plan on the line l0il] of Figure 8.

Figure 11 is a sectional plan taken on the line li ll of Figure 9.

In carrying the invention into effect as illustrated in the accompanying drawings, in the construction of a plant adapted to effect the low temperature distillation more particularly of coal, upon a suitable vertically disposed lattice frame I, there is mounted, for example, at a position about 15 feet from the ground level, the brick work setting 2 for a vertical retort 3, the said setting extending upwardly for about 30 feet. Such setting is provided with a plurality of heating flues extending in any suitable arrangement, but preferably as hereinafter described, and provided either for the combustion of gaseous fuel at the lower end of the fiues or at other suitable positions, or for the introduction of heating gases from some exterior source. The flues are provided with suitable dampers or other means for the control of the temperature conditions at different elevations along the retort. The retort proper is provided in the form of a series of sections of hollow open-ended metal elements having an oblong cross-section, for example, 2 feet in length and 6 inches in width, the ends of the cross-section being of circular or similar smooth curvature and the sections being provided flanged at each end for the formation of connections between them or with other elements of the plan. The lower section of the retort is provided with a footstep or base 4 by which the whole of the retort is supported sole- 1y at the lower end upon the metal frame I, thus to permit free expansion upwardly under heat.

The lateral walls of the retort are advantageously formed with a pair of rubbing strips or rails 5 (Figure 2) by which the containers for the charge may be guided through the retort in their downward passage. The upper end of the retort is provided with an inlet fitting 6 that is adapted to carry the casing of the retort inlet valve, as hereinafter described, and is formed with an oiftake 1 for the gases and vapours of distillation, and the retort together with the said valve casing is adapted for vertical movement under expansion in relation to the means whereby the containers are introduced into the inlet valve, and by which the containers are charged with the carbonaceous material, also as hereinafter described. The said. valve casing may be disposed immediately in line with the retort, or the said fitting may be provided of a form such that the valve casing is disposed off the centre line of the retort.

The setting 2 is advantageously adapted to provide a maximum temperature of, for example, 650 C., which temperature may be uniform from the top to the bottom of the retort 3, or may vary, according to the setting of the dampers in the fiues at difierent elevations along the retort. Under the conditions of operation the temperature within the retort is maintained at about 550 C. as the maximum temperature.

The containers '8 (Figures 4 and 5) for the carbonaceous material to be treated are provided of a cross-sectional form substantially corresponding to that of the retort, but of such size or area as to allow adequate clearance and of a shape which tapers slightly in both directions towards the bottom of the container, which is advantageously formed with a longitudinal opening that is closed by a false bottom 9, preferably provided with projecting studs or knobs l by which it may be manipulated. Each container is to be guided, where necessary, within suitable guideways, and for this purpose at each end of the container there is provided a metal fitting ll having a longitudinal middle rib I2, and at the lower end a shoe l3 substantially following the curvature of the lower end of the container. At the upper end of the container the fittings H are connected by rubbing strips M extending along the upper lateral edges of the container, and at an intermediate position towards the'upper end each fitting is provided with an outstanding stud or trunnion l for a purpose to be hereinafter described. The fittings H at the two ends of the container are advantageously stififened by diagonal members l6 extending across the exterior of the lateral walls of the container and welded or otherwise secured to the fittings H which themselves are preferably welded to the container.

As hereinbefore stated the charged containers 8 are adapted to be supported within the retort 3 in their passage through it by a mechanism provided at the lower end, one container being supported upon another by the shoes I3 of the first resting upon the upper ends of the fittings ll of the second, and the containers resting laterally against the rubbing strips 5 of the retort by one of the rubbing strips M.

The supporting mechanism is contained with in a casing ll (Figures 2 and 3) that is closed except in the direction of the retort and is advantageously formed into two lateral compartments it that are connected by transverse hollow sleeves l9 and are open at the sides 20. The casing H is connected by flanges about the openings 20 to a fiange or lateral face 22 of a lower extension 2| of the retort through which the containers 8 emerge. The said face 22 of the extension 2| is provided with longitudinal openings 23 that register with the openings at the sides 20 of the casing H. The extension 2: is jacketed on the remaining sides for the passage of a cooling medimn, or, if necessary, a heating medium. It is further provided on the inner side of the lateral walls with guides 24 for the trunnions l5 of the containers 8.

The casing ll serves to receive in the compartments it two pairs of sprocket wheels 25 for the guidance of endless chains 26 that are provided at determined intervals with outwardly extending supporting arms 21 for the trunnions 15 of the containers 8. The sprocket wheels 25, and .thus the chains 26, are so disposed that the arms 21 of the respective pairs of chains in their travel around the sprocket wheels are caused to follow a path which is at an acute angle to the longitudinal plane of the retort, that is to say, to the plane of the guides 24, so that the arms 21, in moving downwardly, pass into the path of the containers within the retort extension. One pair of sprocket wheels may be replaced by plain wheels.

The bearings 28 of the spindles 29 for the sprocket wheels 25 are supported upon carrier members 30 conveniently in the form of channel or other section metal, advantageously so provided within the casing ll that the position or inclination of the path of the endless chains 26 in relation to the guides 24 of the retort extension 2| may be varied, while at the position at which the arms 21 of the endless chains 26 are caused to take up the weight of the column of the containers 8 within the retort, the chains 26 are supported against the pressure of the arms by suitable skid bars 3| which also may be adjustably positioned within the casing l'l.

At a position at which the endless chains are caused to pass around the lower sprocket wheels 25, the direction of the lower extension of the retort is advantageously diverted slightly away from the chains 26, so that the containers 8 in their continued movement are diverted to the lower valve casing containing the discharge valve.

It will be understood that the spacing of the arms 27 of the endless chains 26 is such that when the chains are passing along the straight path inclined to the guides 24 of the retort extension 2|, the arms 21 pass below the trunnions l5 of the containers 8 within the lower extension of the retort, and take up the weight of the column, and in the continued movement of the chains around the lower sprockets 25, by reason of the increased distance between the arms which results from the curvature of the chains, the lowermost container 8 is relieved of the weight of the column of containers and is at the same time disengaged from the supporting arms 21 to fall by gravity into the discharge valve.

The inlet and discharge valvesfor the containers (Figures 2, 4 and 5) are substantially similar in construction. The casing 32 comprises a cylindrical drum having end closure plates 33, 34, one of which, 33, is provided with a cylindrical recess 35 at the centre for the reception of a stub spindle 36 at one side of the valve 31, while the other cover plate, 34, is provided with a gland and stufiing box 38 for the passage of the spindle 39 of the valve by which movement is imparted thereto from suitable driving gear. The casing 32 of the valve is provided with two openings 48, 4| having suitable flange-connecting fittings for connection to the retort or other element to which the casing is applied, and such openings are advantageously offset from a diameter. The drum 31 forming the valve which is adapted to rotate within the casing 32 and completely to on the casing is provided with a longitudinal through space or pocket 42 for the reception of a single container 8 together with the fittings H applied thereon. In the oscillation of the drum 3'! the said space 42 is brought into alignment first with the inlet opening 40 of the valve casing 32, and secondly into alignment with the outlet opening 4! of the casing. Thus when the space 42 is inalignment with the inlet opening 48, the container 8 may pass by gravity into the valve 31, the valve being closed against the exit 4|, while when the valve has oscillated the inlet opening 40 of the casing is closed, and the space 42 within the valve is brought into alignment with the exit opening 4| of the valve casing, the inlet opening 40 being closed. The container 8 within the valve may then pass into the retort in the case of the inlet valve, or into the discharge casing in the case of the discharge valve.

When the valve 3'! is in that position in which the space 42 therein is in alignment with the inlet opening 40 of the valve casing, it is also advantageously brought into alignment with a shallow recess 43 in the wall of the casing 32 of the valve, which recess may be formed by outwardly diverting the wall of the casing. Such recess or depression forms a striking bed for the incoming container, and since it is recessed from the wall of the valve any damage to the surface that results from the impact of the containers does not affect the efiiciency of the valve as a gas-tight element. The recess or depression may be lined with a suitable substance, such as a relatively soft metal, to break the shock of the containers.

The discharge valve at the lower end of the extension 2| of the retort is provided to discharge the containers 8 into a casing 44 (Figures 1 and 2) having a downwardly inclined lower wall and provided on the lateral walls with guides 45 for the trunnions I5 of the containers 8 by which the containers are guided into a position below the lowermost sprocket wheels 46 of the endless chains 4'! of the chain conveyor by which the discharged containers 8 are carried to the upper end of the retort. The said chain conveyor is provided with arms 48 similar to the arms 21 of the chains 28, but in view of the fact that the chains 47 of the elevator are driven at a higher rate of speed than the chains 26, the arms 48 are spaced at wider intervals. As the containers 8 pass below the said sprocket wheels 46 they are engaged by the arms 48 of the chain conveyor and carried around the sprocket wheel, while their trunnions l5 are still in engagement with the guides 45 and so that they are inverted over a discharge opening 49 through which the contents of the containers may discharge into a suitable receptacle, such as a truck. The guides for the containers on the casing 44 may be so provided that a portion may be removed or may be hingedly mounted so that at will a container or containers may be withdrawn or inserted.

The empty containers 8 are lifted by the conveyor to the upper end of the retort 3 where they again pass around the sprocket wheels 50 of the conveyor, their trunnions l5 still being in engagement with guides 45. On approaching the inlet valve the guides 45 are diverted from the sprocket wheels 58, so that the containers 8 now in their upright position may be led to a suitable position below a delivery chute 5|. The chains 47 of the chain conveyor after passing around the upper sprocket wheels 58 are carried downwardly over idle sprockets to the lower sprocket wheels 45.

There are provided above the casing 32 of the retort inlet valve and in suitable disposition in relation thereto the fixed delivery chute 5| distanced from the casing of the inlet valve in accordance with the depth of a container, a calibrator in the form of a hopper of determined size disposed above the delivery chute 5| and above the calibrator a supply bunker 54. In order that the carbonaceous material present in the supply bunker may be preheated the walls of the bunker are jacketed and from the waste gas flue of the furnace setting 2 heating the retort 3 a conduit 55 extends upwardly and is connected to the upper part of the bunker jacket. At a position adjacent the outlet of the bunker and preferably upon the opposite side there is connected to the jacket a conduit 51 leading to the suction side of the centrifugal exhauster 58 that is motor driven. The delivery of the exhauster is connected to a conduit 59 which extends upwardly for discharge of the gases into the atmosphere and advantageously also extends downwardly into the furnace setting so that the gases drawn through the bunker jacket may be discharged at will either to the atmosphere or for return to the furnace. Provision may be made for diverting the flow of the gases by means of a suitable valve. Similarly, the conduit leading to the bunker may be provided with a by-pass conduit 68 leading direct to the suction side of the exhauster so that at will the transmission of gases through the bunker jacket may be interrupted by operation of suitable valves.

The bunker 54 and the calibrator 55 are provided with valves or closure plates BI, 62 respectively that are oscillatable and are operated in suitable relation to the operation of the retort inlet valve 31.

In the feed of carbonaceous material into the calibrator 55 the valve 6| of the supply bunker is caused to dwell in the open position until the fuel fed into the calibrator is arrested by the formation of a wedge-like mass at the mouth of the bunker. The bunker valve is then caused to cut through the mass of carbonaceous material. calibrator may be adjusted the calibrator is advantageously supported from the bunker by means of adjustable bolts 53 or suspension members so that its elevation in relation to the bunker may be varied.

For the drive of the retort inlet valve 31 there are provided two toothed wheels 64, 65 carrying upon their lateral faces in the one case a stud 66 and in the other case an interrupted cam surface 51 for the oscillation in the opposed directions of the spindle 39 of the valve 32 through the medium of two fixed pawls 68, 69 respectively .co-operating with the two toothed wheels 64, 65. The drive to the toothed Wheels is effected by a driving shaft 10 that is provided with two driving wheels H, 12 of the same diameter, one of which is directly in engagement with the toothed wheel 65 carrying the cam surface of extended length 61, and the other of which is laterally disposed with reference to the toothed wheel 54 carrying the stud 56 and engages an idle wheel 13 upon a counter spindle 14, which idle wheel is of a width to engage both the offset driving wheel 12 and the toothed wheel or cam 64 carrying the stud 66. The toothed wheel 65 bearing the cam surface 61 of extended length advantageous is provided with a roller 14 at or forming the beginning of the cam surface to enable the pawl 69 to mount the cam surface without undue stress. Similar pawls and oppositely rotating toothed wheels are provided in respect of the valve or closure plate of the bunker and the calibrator, and also for the discharge valve of the retort.

In order that the amount received into the For the driving of the several mechanisms there is provided an electric motor which serves through a reduction gear I5 such as a worm and worm wheel to drive an intermediate spindle I6, which through bevel gear 11, is set to drive a spur wheel I8 that serves for the rotation of a spur wheel I9 upon the spindle of theupper main chain wheels 50. The intermediate spindle 18 also serves through bevel gear 80 to drive a spindle 8| extending vertically downwards along the setting for the transmission of the drive to the wheels 25 of. the lowering device and the driving mechanism of the discharge valve. Alternatively, a separate motor drive may be provided at the lower end of the retort and the vertical shaft may be omitted. Very little power is, however, required since so far as the lowering mechanism is concerned this is largely driven by the weight of the containers. The intermediate spindle I6 serves further through bevel gear 82 to drive a spindle 83 disposed parallel with the upper main chain wheel spindle and adapted to carry a chain wheel 84. The said chain wheel is linked by an endless chain 85, advantageously having detachable links, to a corresponding chain wheel 86 on the driving spindle or shaft I0 for the mechanism by which the retort inlet valve is oscillated. In view of the fact that the retort will expand upwardly by an amount of, say, four inches, it is necessary to provide for adjustment of the position of the second chain wheel 86. For this purpose an idle chain wheel 81 is suspended upon links 88 pivotally connected to the framework I of the plant and subjected to the action of a weight 89 tending to force the suspended chain wheel 81 in the direction away from the first and second chain wheels 84, 86 and thus to take up the flack of the chain 85. The spindle 83 of the upper chain wheel also serves to carry the driving wheels for the toothed wheels or cams of the mechanism for effecting the movement of the calibrator valve 92. The spindle 99 upon which the said toothed wheels or cams are mounted is connected through spur gear 9| to a counter spindle 92, while the latter spindle is in turn connected through spur gear 93 with a spindle 94 which serves as the driving spindle for the toothed wheels or cams of the mechanism operating the pawls of the valve BI for the supply bunker.

In respect of each of the pawl mechanisms comprising the oppositely rotating toothed wheels or cams and the pairs of pawls fixed upon the driven spindles, it is advantageous to provide stops to limit the movement of the pawls in the direction in which they are impelled by the respective cams. This ensures against undue movement of the respective valves.

The container guides extending over the upper main chain wheels and to the charging position for the containers are provided with means for retarding the movement of the containers and avoiding shock on their arrival upon the supporting surface of the retort inlet valve 31. A plate-like resilient retarding member 95 is fixed in the upper or outer part of the guides. A pivoted retarding member 96 is mounted upon the upper side of the main guide and extends towards the lower side of the said guide. It is provided with lugs which are connected by links 91 to arms fixedly mounted upon a spindle 98 extending transversely at the exterior of the main guides and also carrying a fixedly mounted arm or arms which in turn is or are connected by links 91' to similar arms mounted upon a spindle 99 at the inner side of the main guides.

The said spindle is further provided with an arm or arms I00 mounted thereon which projects or project into the path of teeth IllI carried by the upper main chain wheel or wheels 50 so that by the turning of the spindle 99 the retarding member or members 96 are moved to permit the container 8 engaged thereby to pass to the filling position. The spindle 99 may be subjected to the action of a spring or springs or be weighted in such manner that the pivoted retarding memberstend to maintain their positions adjacent the inner sides of the main guides.

In order that the container arriving upon the supporting surface of the retort inlet valve 31 may be thrown over into the position to receive a charge from the delivery chute the inner side of the main guide is provided with a pivoted flap member I02 against which the containers rest when received upon the inlet valve. The said flap member is mounted pivotally upon pivots transverse to the path of the containers and is further linked by suitable link members I03 that extend forwardly to a position substantially at the far side of the retort at which the said members are supported by suspension arms or links I04 having fixed pivotal points upon the framing of the plant. The said link members serve to support rollers I05 or like elements which co-operate with rotatable cams I08 of suitable form that are caused to give an intermittent reciprocatory movement to the flap member I02 that is timed to the arrival of the containers and the required disposition of their mouths below the delivery chute 5|. The cam or cams I06 may conveniently be provided upon the counter spindle 92 before referred to and the flap member I02 is advantageously provided to be applied to the container with some degree of resilience. For this purpose at some position between the flap member and the suspension member of the connecting rod a resilient connection is provided. This may comprise a telescopic spring box I0'I upon the connecting rod, the rod being made in two portions and the spring serving as the connection between the two portions. The flap member may also be mounted under the action of a weight tending to bring it into the normal position. The return movement of the flap member may, however, be effected under the action of springs or under the action of the cam which may be formed to effect the positive movement of the flap members in each direction.

There is advantageously provided in the flap member or members at the upper end adjacent the position at which the mouth of the container comes to rest a slot or slots through which any overflow or surplus of the charge may pass from the container to a delivery chute or slideway.

The position of the container below the delivery chute is advantageously determined by buffers or stops that are of adjustable position. It is preferred so to dispose the stops that the container is positioned with its mouth slightly out of coincidence with the mouth of the chute in the direction in which the carbonaceous material tends to flow.

The bunker 54 may receive supplies from an elevated bunker 52 fed by suitable means, such as a skip hoist 53.

In the operation of the plant in the treatment of coal it is preferred to charge the containers 8 with coking coal and to apply to the surface of the charge a layer of non-coking coal. Such procedure serves toprevent the overflowing of the charge through swelling. For the purpose there may be provided a separate supply bunker which is caused to deliver through the calibrator a suitable charge of the non-coking coal upon the surface of the coking coal before or after it passes into the container.

The setting 2 is provided with a centrally disposed vertical chamber h for the reception of the retort 3, the said chamber being flanked by combustion passages or fiues i that extend parallel with the retort chamber and at intervals throughout the length are provided with transverse tie bricks 7' disposed in staggered relation to serve as a form of checker work and to tie the inner walls of the said passages in position. The

inner Walls are provided of relatively small thickness and are conveniently built of panel bricks i having a tongue and groove connection. Thus, the walls between the combustion passages and the retort chamber are maintained of a thickness which permits the ready transmission of heat.

At suitably disposed intervals through the length of the setting the combustion passages are provided with burners k for the admission of heating gases, such burners It being supplied from a common supply pipe k extending upwardly along the exterior of the setting. The said burners are thus provided along one side of the combustion passages, while on the opposing side there are provided lengthwise of the setting a number, for example, three air flues l which extend upwardly in parallel with the retort chamber and combustion passages and receive air from suitable inlets 1 extending outwardly of the setting at the lower end. At positions corresponding to those at which are disposed the burners there are provided horizontal air flues l which extend from the vertical supply fiues 1 around the outer side of the combustion passages and serve to deliver air at positions which are in close proximity to the respective burners It. At these positions there may be provided transverse openings Z extending to the exterior of the setting, which openings serve to permit of the ignition of the gases entering the combustion passage 2' from the burners 7c. Such openings are suitably closed by means,of plugs that are removable.

The waste heating gases leave the retort chamber m at the upper end at m and may pass directly to the exterior of the setting by wayof an outlet conduit, such as the conduit 56, or alternatively they may be diverted to a flue which lies parallel with the air fines and may serve additionally to preheat the air before it is admitted for combustion.

At the upper end of the combustion passages or at other suitable positions along the length there may be provided passages m controlled by dampers and serving for the admission of a supply of the waste gases for re-circulation in the combustion passages. Such passages may receive a supply of waste gases from the exterior of the setting, as from the conduit 59, or alternatively from the waste gas exhaust lines by way of by pass passages which may be controlled by dampers or closing bricks for the determination of the proportion of waste gases that shall pass directly into recirculation in the combustion passages.

The control of the dampers by which the recirculation of the waste gas is eiTected may be carried out by way of control openings m extending to the exterior of the setting and closed by removable closure plates or plugs.

The parts of the settings which are subject to high temperatures are advantageously constructed of refractory brickwork n. This may be encased in a shell of insulating brickwork n which in turn may be enclosed within an outer wall 11. of red bricks.

As illustrated in Figure 1, the movement of the containers in the charging position to register with a fixed delivery chute may be avoided by providing that the material is delivered from the calibrator into a hinged shoot that is caused to swing from aposition below the calibrator into a position in which the contents may be discharged into the empty container 8 then resting upon the upper surface of the inlet valve 31.

It will be understood that the operation of the chain conveyor, the charging shoot, the inlet valve, the container supporting mechanism and the discharge valve may be effected from a common driving mechanism. Alternatively the drives may be eiiected independently, suitable means being provided to secure synchronism.

It will further be understood that the setting 2 may be provided to serve for a plurality of retorts, and further that the retort may be provided to operate with a plurality of lines of containers.

Instead of providing containers to move vertically downward in their course through the retort or carbonizing zone they may move in an inclined position, but as hereinbefore described it is preferred to provide for the movement of the containers vertically downward or at an inclined position at a small angle to the vertical.

The inverted containers may advantageously be returned from the lower position of their course to the upper charging position through a casing through which also that part of the chain conveyor may return downwardly adjacent the retort setting.

A star wheel or other device may be provided at a position immediately before that at which the discharging aperture is provided for checking the containers from overrimning the chain conveyor.

It will further be understood that the invention is not limited to the details of construction of the retort, the setting, or the associated mechanisms as illustrated in the accompanying diagrammatic drawings where these are clearly capable of modification without departing from the scope of the invention.

Thus, where the movements of the oscillatory r members or valves are effected from a single cam and pawl mechanism the operating spindles of certain of the oscillatory members may be operated from such cam and pawl mechanism through link mechanism. Again, while the flap member for turning the container into the position to receive the charge from the fixed delivery chute may be operated by teeth'provided upon the main chain wheel it is also possible, and in certain cases, perferable, to operate the flap from teeth provided upon the main chains. In such an arrangement the members that serve for supporting the containers upon the chains may serve this purpose wherethe spacing of the supports in the length of the chains and in relation to the flap mechanism is suitable. It may in certain instances be desirable to provide a take-off for the gases of distillation at the lower end as well as at the upper end of the retort. Thus, an ofitake may be provided at the lower end of the retort as is indicated in dotted lines in Figure 2 of the accompanying drawings.

The cams that are employed to eiiect the move- V ments of the valves may be of a form positively to effect the movements in their entirety or they may be of a form to effect the movement in one direction against the action of a restraining force applied either by springs or weights. Similarly, the manner in which the several moving parts are driven may be modified without departing from the invention, since any convenient gearing that will permit of the synchronisation oi the several parts so that they operate in the required sequence may be provided.

The interior of the bunker jacket may be provided with bafiles to afiord a tortuous path for the waste gases or air through it.

In certain applications it may be found desirable to provide for the withdrawal of the gases and vapours of distillation from the lower end of the retort, as illustrated by the off-take represented in broken lines in Figure 2. Such an offtake may be additional to, or in place of, the offtake at the upper end of the retort.

I claim:

1. In an apparatus for effecting the distillation of coal or other carbonaceous substances, a setting, a substantially vertical retort arranged in the setting, means in the setting for applying heat to the retort, guideways extending downwardly from the lower end of the retort, a plurality of separate containers for the carbonaceous substance, each of said containers having relatively flat sides and adapted to slide through the retort and said guideways by gravity, resting upon one another in a column, a container lowering mechanism adjacent said guideways comprising an endless conveyor having a series of spaced supporting arms which move, in succession, into the path of the column and engage and support the lowest container in the column and then move downwardly "out of the path of the column to lower the column and to release the lowermost container after another arm on the conveyor has moved into position to support the succeeding container and the column,

2. An apparatus as in claim 1 in which each container has flattened sides converging toward the bottom and is provided with fittings for seating the lower end of one container upon the upper end of another container, said fittings having trunnions projecting oppositely from the edges of the container at its upper end.

3. In an apparatus for effecting the distillation of coal or other carbonaceous substances, a setting, a substantially vertical retort arranged in the setting, means in the setting for applying heat to the retort, guideways extending downwardly from the lower end of the retort, a plurality of separate containers for the carbonaceous substance, each of said containers having relatively fiat sides and adapted to slide through the retort and said guideways by gravity, resting upon one another in acolumn, a container lowering mech-- anism adjacent said guideways comprising an endless conveyor having a series of spaced supporting arms which move, in succession, into the path of thecolumn and engage and support the lowest container in the column and then move downwardly out of the path of the column to lower the column and to release the lowermost container after another arm on the conveyor has moved into position to support the succeeding container and the column and a valve at the lower end of said guideways adapted to receive each container when released from the lowering mechanism, said valve comprising a casing and a drum therein moveable about a horizontal axis, said casing having an inlet opening in its upper part and a discharge opening in its lower part, out of line with the inlet opening, and said drum having athrough opening adapted to hold a container and adapted to register with the inlet opening only in one positionof the drum and with the outlet opening only in another position of the drum.

4. An apparatus as in claim 3 and a similar valve at the upper end of the retort for feeding the containers one by one into the retort.

ROBERT NISBET. 

